Jump to content

TR6 J Type overdrive relay


Recommended Posts

Hello

I am rewiring my 1973 TR6 which has a J type overdrive and was just wondering if it is necessary to have a relay in the circuit, there seems to bee contrasting views on this subject?

If it is a requirement could anyone supply/point me in the direction of a wiring diagram for the relay. I have a basic idea but would like to confirm these details.

Kind Regards

Andrew

Link to post
Share on other sites

No need for a relay Andrew. The J type solenoid draws only around 2 Amps which is well within the capability of a normal switch.  

Are you intending to have a 'logic unit' ?  Many users consider it worthwhile; as the name suggests it makes the operation rather more logical. There have been several alternative circuits posted in previous threads. 

Edited by RobH
Link to post
Share on other sites

Normally when you switch the overdrive on, it stays on even if you change gear (between 3rd and 4th on a J type).  With it on you find yourself going from 2nd to 3rd OD to 4th OD changing up and from 4th OD to 3rd OD to 2nd when changing down.  

With a logic unit the overdrive is disconnected at each shift,  so you go from 2nd to 3rd to 3rd OD to 4th to 4th OD - like having a closer ratio gearbox.  On the down change you go from 4 OD to 3rd so you get greater acceleration.  If you want overdrive you have to switch it on again after each gear change.   Instead of the standard on-off overdrive switch you can use a 'momentary' one - a flick switch - some people fit a push-button on the gear knob. 

There are some (rather expensive) ready-made units available like the one from Revington, or if you are happy dabbling with electrics you can make your own using a few readily available bits at a fraction of the price. 

Here are a couple of earlier threads:

https://www.tr-register.co.uk/forums/index.php?/topic/76663-over-drive-logic-revisited/

https://www.tr-register.co.uk/forums/index.php?/topic/78482-home-brew-overdrive-logic-controller/&tab=comments#comment-740865

 

Link to post
Share on other sites

See my article in TR Action 203 (May 2005) for a description of Revington's offering.

Members of the Register can view all copies of TR Action (and Newsletters) by logging in to the Register's website.

Ian Cornish

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.